ARGUMENTS OF INTERPRETATION AND ARGUMENTATION SCHEMES Fabrizio Macagno 1. Introduction In everyday discourse we retrieve the meaning of verbal or written utterances by means of different processes of reasoning. The most common one is the presumptive, or rather heuristic mechanism (Ham- blin 1970, pp. 294-295; Macagno 2012). Our interpretation of a word or a sentence is guided by the commonly shared definition and meaning attributed to it. However, sometimes the presumptive meaning is not a viable option. If we do not have any doubts in classifying an unlawful killing as a ‘homicide’, we have much greater problems when we need to categorize an abortion as such. There are cases in which we cannot presume a shared meaning, or the shared meaning itself is contested. Therefore, the possible definition of a word or the interpretation of a sentence becomes a standpoint that needs to be supported by argu- ments. In this sense, the actual or possible conflicts of opinion on meaning become a form of argumentative practice that needs to be ana- lyzed through the analysis of the arguments used. Theories on legal interpretation clearly highlight this argumentative dimension of meaning. According to McCormick (1995, p. 467), inter- pretation ‘is a particular form of practical argumentation in law, in which one argues for a particular understanding of authoritative texts or materials as a special kind of (justifying) reason for legal decisions.’ A statement of law (or source statement) can be used to support a specific conclusion only by retrieving its meaning. Sometimes this meaning can be reconstructed in a presumptive way, and in this sense we ‘under- stand’ it. However, when the understanding of the source is controver- sial, it turns into an interpretative process grounded on arguments (Pat- terson 2004, p. 247).