Now, if I am not mistaken, Plantinga is a foundationalist (of whatever type). According to which it is alright to say that he believes there are basic beliefs and derived beliefs. And that, the derived beliefs depend on basic beliefs for support, directly or indirectly.
What is warrant? It is the property that makes a true belief knowledge. Some beliefs require only warrant. And some require justification. Beliefs that require only warrant are obviously basic beliefs because justification here means doxastic justification, or propositional justification (which comes from other beliefs). And we know for sure that basic beliefs do not require that to become knowledge.
Now, let’s bring proper function into the picture. Proper function is necessary for warrant, says Plantinga. For basic beliefs, proper function provides a degree of warrant which is sufficient to make them knowledge. And for derived beliefs proper function provides a degree of warrant that is insufficient. Warrant, in this case, requires doxastic justification. What is proper function?
According to the central and paradigmatic core of our notion of warrant (so I say) a belief B has warrant for you if and only if (1) the cognitive faculties involved in the production of B are functioning properly . . . (2) your cognitive environment is suciently similar to the one for which your cognitive faculties are designed; (3) . . . the design plan governing the production of the belief in question involves, as purpose or function, the production of true beliefs . . .; and (4) the design plan is a good one: that is, there is a high statistical or objective probability that a belief produced in accordance with the relevant segment of the design plan in that sort of environment is true. (Plantinga 1993)
Plantinga’s theory depends on the existence of a God. He has to be there to govern our cognitive faculties and make sure that they are working right. Proper function is necessary for warrant (sufficient in cases of basic beliefs and insufficient in cases of derived beliefs). Warrant is sufficient and necessary to make a true belief knowledge.
Here is another debate. Doxastic justification can strengthen basic beliefs but they are not necessary to make those true basic beliefs knowledge, says who? Says Mark Boone. And a few others but then I haven’t read them as primary source. Peter Tramel tells us that Chisolm says justification of basic beliefs can be improved upon through coherence with other justified beliefs. Haack tells us that Roderick Firth and Bertrand Russell gave this ‘passing attention’ as well. This debate deals with the basic question, what is foundationalism? Now, do we have a proper answer to this question? I think I should probably write another post for this. So let’s just leave it here.
P.S. I am going to read an article by Jonathan L. Kvanvig and it’s called Plantinga’s Proper Function
Account of Warrant.