It is commonly known that C. I. Lewis started modern modal logics (S1-S5) because of his dissatisfaction with material implication. But his original intention was to construct a logic of strict implication rather than a logic of modality. Then he had got involved in the latter gradually against his original intention. In this paper, I clarify where his original intention lay and how he was involved in modal logics tracing his writings chronologically. Considering his contemporary logicians' responses, I sum up the argument.
It is thought that the problem of self-deception is difficult to treat because it includes a paradox. I investigate under what conditions self-deception occurs, rather than how the paradox is solved. I think one of the important conditions of selfdeception is that the two apparently contradicting beliefs coexist without either of them being unconscious. After surveying the discussions concerning whether self-deception is intentional, I focus on the role of "motivation", following Alfred Mele, and try to state the necessary and sufficient conditions of self-deception on the basis of the motivations and situa-tions of the self-deceivers.
The notion of truth conditions of sentences or psychological states plays important roles in various areas of philosophy, but authors who appeal to this notion rarely explain exactly what attribute of those entities truth conditions are. Indeed, there are two notions (not always clearly distinguished) that can legitimately be called the notions of truth conditions, and these are definable by reference to different semantical frameworks. It turns out that there is an important systematic relationship between the two notions, explicitly definable within Kaplan's theory of demonstratives, and this reveals that the two kinds of truth conditions are to be attributed to entities of different ontological types.
Swampan poses a problem for physicalists who adopt the teleological approach to functionalism. In this paper I reformulate the intuitive idea behind the physicalists' worry about it as "Swampman argument", and consider possible rejoinders, including Maeda (1999)'s claim that swampman is not even imaginable. This paper was originally intended as a comment on Maeda's reply to Mizumoto (2000), which criticized his (1999).
One of alleged problems of Wittgenstein's Tractatus logico-philosophicus (TLP) is that we could give no example of its basic concepts such as elementary propositions, names, states of affairs, simple objects, and so on. The problem is so serious, because it means that the whole theoretical system of TLP could have no applicability. Noya, in his recent book on TLP, proposes to regard ordinary objects familiar to us in our daily life, such as persons, dogs, mountains, rock bands, and so on, as examples of simple objects of TLP. But, I think, we cannot interpret TLP in the way his proposal suggests. In this paper I shall show there is no sense in which we can say ordinary objects are simple objects of TLP. There are two main reasons. One concerns TLP's requirement of logical independency of elementary propositions, and the other concerns TLP's requirement that simple objects should exist independently of what is the case.
This book is the last book of Iida's celebrated series, "Summa". It includes a detailed argument for homophonic semantics and an equally detailed exposition of his truth-conditional semantics for three fragments of Japanese, the third of which contains indexical expressions and tensed verbs. As one might expect, the semantics given for this fragment is far from being homophonic. I will examine what role his argument for homophonic semantics plays in his defense of his non-homophonic semantics. I will also examine how Iida avoids treating moods in his semantics, and point out the need to treat illocutionary acts within semantics.