In his book Wittgenstein on Rules and Private Language (1982) Saul Kripke claims that Wittgenstein argues for a certain form of scepticism in his book Philosophical Investigations (1953), namely a new form of philosophical scepticism, a result of Wittgenstein´s idea of language as language games. Nihilism, scepticism of meaning or of concept, constitutive scepticism are other commentators´ different names of the same phenomenon. The philosophy of Wittgenstein accounts for how our words, including the words of mathematics, have no meaning and there are no a priori justified objective facts as to what I mean about a word. We follow the rules blindly and without justification. We are unable to find any facts against this proposal.

 In his book Wittgenstein on Rules and Private Language (1982) Saul Kripke claims that Wittgenstein argues for a certain form of scepticism in his book Philosophical Investigations (1953), namely a new form of philosophical scepticism, a result of Wittgenstein´s idea of language as language games. Nihilism, scepticism of meaning or of concept, constitutive scepticism are other commentators´ different names of the same phenomenon. The philosophy of Wittgenstein accounts for how our words, including the words of mathematics, have no meaning and there are no a priori justified objective facts as to what I mean about a word. We follow the rules blindly and without justification. We are unable to find any facts against this proposal.

 In his book Wittgenstein on Rules and Private Language (1982) Saul Kripke claims that Wittgenstein argues for a certain form of scepticism in his book Philosophical Investigations (1953), namely a new form of philosophical scepticism, a result of Wittgenstein´s idea of language as language games. Nihilism, scepticism of meaning or of concept, constitutive scepticism are other commentators´ different names of the same phenomenon. The philosophy of Wittgenstein accounts for how our words, including the words of mathematics, have no meaning and there are no a priori justified objective facts as to what I mean about a word. We follow the rules blindly and without justification. We are unable to find any facts against this proposal.

I den här uppsatsen tänker jag reda ut det epistemologiska begreppet a priori. Att det är ett epistemologiskt begrepp innebär att det handlar om kunskap. Den här kunskapen kan uttryckas i satser. Sådana satser är satser som vi har a priorisk kunskap om. Exempel på vad man brukar kalla a prioriska satser är: ?inget kan vara helt täckt av rött samtidigt som det är helt täckt av grönt? och ?om A kommer före B och B kommer före C så kommer A före C? eller mer metafysiska utsagor som ?ett fysiskt objekt kan inte vara på två ställen vid samma tidpunkt? och ?alla effekter måste ha en orsak?, men som främsta exempel brukar man tala om logiska eller matematiska utsagor.

The paper contains comment, clarification and criticism, even constructive criticism, of some theses that have been put forward by Laurence Bonjour in his In Defense of Pure Reason.It presents a concept of experience that deals with the relation between cognizer and object of experience that has a great similarity to that of Bonjour. Through analysis it is shown that the concept of a priori entails that Bonjour has two concepts of a priori, a narrow and a broad one. The narrow one is, in my own words: According to moderate rationalism a proposition p is a priori justified if and only if you apprehend that p must be true in every possible world. This doesn?t mean that Bonjour doesn?t believe in an epistemological, metaphysical and semantic realm.