1. Introduction
I. What is law?
A system of rules that is normally enforced by collective means and that aim to organise
a society
"and that aim to organise a society"
o The purpose of law is to end or prevent disputes
o The law prefers the certainty of clear result over the uncertainty of the "best"
solution for a problem
II. Sources of law
o Material sources
Provide knowledge about the law, but are not constitutive of law
Formal (or official) sources
Provide legal norms with authority based on their origin and make these legal norms
binding in their effect
o Official sources thesis
o Only a limited set of sources counts as official sources of law
o The formal sources of law differ from jurisdiction to jurisdiction
o The most important official sources of law are:
o Treaties
o Legislation
o Case law
o Customary law
o Contracts
o Fundamental principles of law
The contents of these formal sources are positive law
Functional fields of law
(Business law, European union law, human rights law, avation law, construction law,
education law, public procurement law,…)
o Substantive private law
Family law
Property law
Contract law
Tort law
o Substantive public law
International public law
Constitutional law
Administrative law
Criminal law
o Procedural private law
Civil procedural law
o Procedural public law
Criminal procedural law
Administrative procedural law
Business law
Comprises three fields of law
o Business organisation law
Company law
Associations law
o Business contracts law
IP law
Competition law
Page 1 of 54
, Consumer protection law
Agency law
Insolvency law
Capital markets law
…
o Labour law
Other relevant fields of law are data protection law, environmental law, criminal
law, contract law, liability law, tax law, property law, …
III. Legal families and their main features
Civil law system systems
o Have their origins in Roman law
o Legislation is the most important official source of law
o No case law
Common law systems
o Have their origin in the English legal system
o Case law is the most important official source of law
Religious law systems
o Have a divine origin
o The law emanates from religious texts
o Different subsections
Customary law systems
o Have their origins in patterns of behaviour
o Laws are usually unwritten and are often dispensed by elders
o Passed down through generations
o Laws are deemed immutable
o Also known as the indigenous or chtonic legal tradition
Mixed or hybrid law systems
o These legal families combine traits of two or more legal traditions
Examples:
o Stare decisis: stand by the things decided and do not disturb the calm
"Where a manufacturer sells a product which will reach the ultimate consumer
without possibility of interference, and where inspection is not possible, the
manufacturer owes a duty of care to avoid acts or omissions which one can
reasonably foresee would be likely to injure your neighbour"
This a new legal rule, thatoriginates from the Donoghue v. Stevenson case, and
has to be followed in future cases
Only the ratio decidendi set a binding precedent, not the obiter dicta
Be aware of the importance of case based reasoning in common law systems
o Imagine: we are not in a common law but in a civil law system
"Where a manufacturer sells a product which will reach the ultimate consumer
without possibility of interference and where inspection is not possible, the
manufacturer owes a duty of care to avoid acts or omissions which one can
reasonably foresee would be likely to injure your neighbour"
A judge could have only made this ruling with reference to an offical source of
law
Do not overestimate the difference with the doctrine of stare decisis
▫ Courts in civil law systems are often inclined to follow their own decisions
and those of senior courts in subsequent cases. They try to avoid the
reversal of their decisions by higher courts
▫ Precedents still serve a function as a material source of law
Page 2 of 54
, ▫ Civil law systems often work with "open norms" that leave quite some
discretionary margin of appreciation to the judge
o Equity as a corrective source of law
Legal remedies
▫ Source of law
♦ Legislation
♦ Case law
▫ Principal result
♦ Allows the victim to recover monetary damages
▫ Margin of discretion
♦ Absent
♦ The victim is entitled to a legal remedy as soon as all the conditions are
met
▫ Examples
♦ Action for damages
♦ Exclusive entitlement to goods
Equitable remedies
▫ Source of law
♦ Equity
▫ Principal result
♦ Requires a party to act or refrain from performing a particular act in
cases where legal remedies are not considered to provide sufficient
restitution
▫ Margin of discretion
♦ The grant of equitable relief is at the discretion of the judge
▫ Examples
♦ Action for specific performance
♦ Trusts
IV. The historical development of law in Western Europe
Before 451 BC.: tribal customary (unwritten) law
451 BC.: codification of roman law, the XII Tables
395; split of roman empire
o Western Roman Empire (WRE)
455: plunder of Rome
476: fall of WRE, Germanic tribal law
▫ Continent
♦ 11th Century: University of Bologna, emergence of canon law
rediscovery of the Digest
♦ 12th-17th Century: emergence of Ius commune
♦ 1648: Treaties of Westphalia
Westphalian duo:
National state law
International public law
♦ 1789: French revolution
♦ 19th century: codification of French law and introduction in
conquered countries
◊ French school
Use of codified law
Creation of law is a political process
1945
Page 3 of 54
, Development of transnational law
Rise of human rights
Foundations of the EU
Revival of the Lex Mercatoria
◊ German school
Historical school
<=> creation of law is (mostly)driven by legal scholars
1945
Development of transnational law
Rise of human rights
Foundations of the EU
Revival of the Lex Mercatoria
▫ England
♦ 1066: battle of Hastings, unification of English law => common law
♦ 14th: emergence of equity as an exception to the law
♦ 1789: French revolution
o Eastern Roman Empire (ERE)
529-534: Corpus luris civilis
▫ Codex
▫ Digest
▫ Institutiones
1453: End of the Byzantine empire
V. Legal reasoning
Deductive reasoning or the use of legal syllogism
o The process of reasoning from one or more premises that are assumed to be true to
reach a logical conclusion
o Leads to an indisputable conclusion but only if the premises are indeed true and the
logic has been strictly followed
Inductive reasoning
o The process of reasoning by extrapolating general rules from different cases where
specific facts very
o Leads to the formulation of a general rule that in all probability applies to a specific
case, although you will never be 100% certain
Reasoning by analogy
o Reasoning by analogy involves drawing specific conclusions from other specific
examples based on the similarities
o You try to establish whether the court should follow a similar reasoning or not
VI. Basic concepts of law
Legal subjects
o Natural persons
o Legal persons
Rules, operative facts and legal consequences
o Art. 4 GDPR – Definitions
"for the purpose of this Regulation:"
'personal data' means any information relating to an identified or identifiable
natural person. An identifiable natural person is one who can be identified,
directly or indirectly, in particular by reference to an identifier such as a name,
an identification number, location data, an online identifier or to one or more
factors specific to the physical, physiological, genetic, mental, economic,
cultural or social identity of that natural person
Page 4 of 54
I. What is law?
A system of rules that is normally enforced by collective means and that aim to organise
a society
"and that aim to organise a society"
o The purpose of law is to end or prevent disputes
o The law prefers the certainty of clear result over the uncertainty of the "best"
solution for a problem
II. Sources of law
o Material sources
Provide knowledge about the law, but are not constitutive of law
Formal (or official) sources
Provide legal norms with authority based on their origin and make these legal norms
binding in their effect
o Official sources thesis
o Only a limited set of sources counts as official sources of law
o The formal sources of law differ from jurisdiction to jurisdiction
o The most important official sources of law are:
o Treaties
o Legislation
o Case law
o Customary law
o Contracts
o Fundamental principles of law
The contents of these formal sources are positive law
Functional fields of law
(Business law, European union law, human rights law, avation law, construction law,
education law, public procurement law,…)
o Substantive private law
Family law
Property law
Contract law
Tort law
o Substantive public law
International public law
Constitutional law
Administrative law
Criminal law
o Procedural private law
Civil procedural law
o Procedural public law
Criminal procedural law
Administrative procedural law
Business law
Comprises three fields of law
o Business organisation law
Company law
Associations law
o Business contracts law
IP law
Competition law
Page 1 of 54
, Consumer protection law
Agency law
Insolvency law
Capital markets law
…
o Labour law
Other relevant fields of law are data protection law, environmental law, criminal
law, contract law, liability law, tax law, property law, …
III. Legal families and their main features
Civil law system systems
o Have their origins in Roman law
o Legislation is the most important official source of law
o No case law
Common law systems
o Have their origin in the English legal system
o Case law is the most important official source of law
Religious law systems
o Have a divine origin
o The law emanates from religious texts
o Different subsections
Customary law systems
o Have their origins in patterns of behaviour
o Laws are usually unwritten and are often dispensed by elders
o Passed down through generations
o Laws are deemed immutable
o Also known as the indigenous or chtonic legal tradition
Mixed or hybrid law systems
o These legal families combine traits of two or more legal traditions
Examples:
o Stare decisis: stand by the things decided and do not disturb the calm
"Where a manufacturer sells a product which will reach the ultimate consumer
without possibility of interference, and where inspection is not possible, the
manufacturer owes a duty of care to avoid acts or omissions which one can
reasonably foresee would be likely to injure your neighbour"
This a new legal rule, thatoriginates from the Donoghue v. Stevenson case, and
has to be followed in future cases
Only the ratio decidendi set a binding precedent, not the obiter dicta
Be aware of the importance of case based reasoning in common law systems
o Imagine: we are not in a common law but in a civil law system
"Where a manufacturer sells a product which will reach the ultimate consumer
without possibility of interference and where inspection is not possible, the
manufacturer owes a duty of care to avoid acts or omissions which one can
reasonably foresee would be likely to injure your neighbour"
A judge could have only made this ruling with reference to an offical source of
law
Do not overestimate the difference with the doctrine of stare decisis
▫ Courts in civil law systems are often inclined to follow their own decisions
and those of senior courts in subsequent cases. They try to avoid the
reversal of their decisions by higher courts
▫ Precedents still serve a function as a material source of law
Page 2 of 54
, ▫ Civil law systems often work with "open norms" that leave quite some
discretionary margin of appreciation to the judge
o Equity as a corrective source of law
Legal remedies
▫ Source of law
♦ Legislation
♦ Case law
▫ Principal result
♦ Allows the victim to recover monetary damages
▫ Margin of discretion
♦ Absent
♦ The victim is entitled to a legal remedy as soon as all the conditions are
met
▫ Examples
♦ Action for damages
♦ Exclusive entitlement to goods
Equitable remedies
▫ Source of law
♦ Equity
▫ Principal result
♦ Requires a party to act or refrain from performing a particular act in
cases where legal remedies are not considered to provide sufficient
restitution
▫ Margin of discretion
♦ The grant of equitable relief is at the discretion of the judge
▫ Examples
♦ Action for specific performance
♦ Trusts
IV. The historical development of law in Western Europe
Before 451 BC.: tribal customary (unwritten) law
451 BC.: codification of roman law, the XII Tables
395; split of roman empire
o Western Roman Empire (WRE)
455: plunder of Rome
476: fall of WRE, Germanic tribal law
▫ Continent
♦ 11th Century: University of Bologna, emergence of canon law
rediscovery of the Digest
♦ 12th-17th Century: emergence of Ius commune
♦ 1648: Treaties of Westphalia
Westphalian duo:
National state law
International public law
♦ 1789: French revolution
♦ 19th century: codification of French law and introduction in
conquered countries
◊ French school
Use of codified law
Creation of law is a political process
1945
Page 3 of 54
, Development of transnational law
Rise of human rights
Foundations of the EU
Revival of the Lex Mercatoria
◊ German school
Historical school
<=> creation of law is (mostly)driven by legal scholars
1945
Development of transnational law
Rise of human rights
Foundations of the EU
Revival of the Lex Mercatoria
▫ England
♦ 1066: battle of Hastings, unification of English law => common law
♦ 14th: emergence of equity as an exception to the law
♦ 1789: French revolution
o Eastern Roman Empire (ERE)
529-534: Corpus luris civilis
▫ Codex
▫ Digest
▫ Institutiones
1453: End of the Byzantine empire
V. Legal reasoning
Deductive reasoning or the use of legal syllogism
o The process of reasoning from one or more premises that are assumed to be true to
reach a logical conclusion
o Leads to an indisputable conclusion but only if the premises are indeed true and the
logic has been strictly followed
Inductive reasoning
o The process of reasoning by extrapolating general rules from different cases where
specific facts very
o Leads to the formulation of a general rule that in all probability applies to a specific
case, although you will never be 100% certain
Reasoning by analogy
o Reasoning by analogy involves drawing specific conclusions from other specific
examples based on the similarities
o You try to establish whether the court should follow a similar reasoning or not
VI. Basic concepts of law
Legal subjects
o Natural persons
o Legal persons
Rules, operative facts and legal consequences
o Art. 4 GDPR – Definitions
"for the purpose of this Regulation:"
'personal data' means any information relating to an identified or identifiable
natural person. An identifiable natural person is one who can be identified,
directly or indirectly, in particular by reference to an identifier such as a name,
an identification number, location data, an online identifier or to one or more
factors specific to the physical, physiological, genetic, mental, economic,
cultural or social identity of that natural person
Page 4 of 54
