subsequent liabilities must be sufficiently explicit to guarantee
individuals a margin of certainty regarding the possible liability
of their expressions. (...)
I believe that the rules of the criminal code are excessively
ambiguous and broad and do not clearly establish the
components of the crime, because they do not specify the
intent required of the active subject, allowing the subjectivity
of the offended party to determine the existence of the crime.
(...)
There is a principle of legality with respect to the articles, but
in this case they do not comply with the requirement of clarity
because the criminal definitions applied were too broad and
vague, making it impossible to anticipate the conduct. So,
there is no correspondence with the principle of legality in the
norms applied in this specific case.
74. The case law of the Inter-American Court has long been consolidated in the sense
that the definitions of criminal law must not only be formulated prior to the criminal
act, but also in an express, accurate and exhaustive manner, using precise and
unequivocal terms that identify the criminalized conduct. 54 This requirement of
certainty or principle of specificity is one of the corollaries of the principle of
legality 55 in criminal law, also known by its Latin formulation nulla poena sine lege,
coined by Anselm Von Feuerbach, who derived it from his theory of psychological
coercion. In order for a penalty to fulfill the function of encouraging citizens not to
commit crimes, it is necessary that they know in advance precisely what the
criminal law prohibits. 56 However, the principle of legality is not limited to this
teleological or consequentialist argument 57 - it also has a political-democratic
basis, of a deontological nature: the executive and judicial powers are bound by
abstract laws that protect the individual from the arbitrariness of the State.
Moreover, restrictions on the freedom of citizens – such as criminal laws par
excellence - should only be determined by the democratically empowered
legislator. 58 Thus, the requirement of certainty, derived from the principle of legality,
means that criminal law must be sufficiently clear and precise so that those involved
can know and understand the prohibited conduct, guaranteeing them a margin of
legal certainty as to the possible liability for their statements. In a State governed
by the rule of law, the predictability and reliability of the exercise of state power in
the criminal sphere are values linked to the principle of legality. This means that a
judge must be able to extract from the criminal law reliable guidance for its
application in a specific case, while citizens must be able to clearly visualize the
limits of permissible behavior and the nature and severity of the sanction that
awaits them if they infringe those limits. 59
54
Cf. Case of Ricardo Canese v. Paraguay. Merits, reparations and costs. Judgment of August 31, 2004. Series
C. No. 111, §174; Case of Kimel v. Argentina. Merits, reparations and costs. Judgment of May 2, 2008. Series
C. No. 177, §63 and Case of Usón Ramírez v. Venezuela. Preliminary objection, merits, reparations and costs.
Judgment of November 20, 2009. Series C No. 207, §55.
55
Beside the others: nulla peona sine lege scripta (prohibition of basing punishment on customary or natural
law), praevia (prohibition of retroactivity), and stricta (prohibition of analogy).
56
Further references SCHÜNEMANN, Bernd. Nulla poena sine lege, Berlin/New York: Walter de Gruyter, 1978, p.
2; GRECO, Luis. Lo vivo y lo muerto en la teoría de la pena de Feuerbach, Madrid/Barcelona/Buenos Aires/São
Paulo: Marcial Pons: 2015, p. 55.
57
For a critique of the purely teleological basis of the principle of legality, cf. GRECO, Luís. Conveniencia and
respeto: sobre lo hipotético y lo categórico en la fundamentación del derecho penal, Indret 4/2010, p. 5 sbsq.
58
GARCIA PÉREZ, Octavio. El principio de legalidad y el valor de la jurisprudencia, Indret 4/2018, p. 8; ROXIN,
Claus/GRECO, Luís. Strafrecht Allgemeiner Teil, Band I, 5th ed., 2020, p. 219.
59
URBINA GIMENO, Iñigo Ortiz de, ¿Leyes taxativas interpretadas libérrimamente? Principio of legality and
interpretation of the derecho penal”, in: MONTIEL, Juan Pablo (ed.). La crisis del principio de legalidad en el