Conjectural Knowledge

The idea that knowledge is conjectural may at first seem contradictory. In fact, it is contradictory. Traditionally, knowledge is defined in contrast to conjecture, so where it would make sense to say that a conjecture is either true or false, to say that knowledge is false would be nonsense. If you know that the earth orbits the sun, then to add that it is also true would be redundant, since to know something is to say that it is true and that you have checked, confirmed, or justified your belief that it is true. Indeed, if a conjecture is justified then it is elevated into the realm of knowledge, and so to say that knowledge is conjectural is as absurd as saying that black is white, rainbows are people or that green is grass.

The mistake with this objection is that it ignores the problem for which the concept of conjectural knowledge is an attempted solution. The problem is that every valid argument is circular, and therefore the premises of an argument cannot justify any conclusion which we validly derive from them. The alternative is to try and justify a conclusion using an invalid argument, and as strange as this may seem it is precisely the road which the vast majority of philosophers have taken. This move is exemplified by the widespread adoption of a principle of induction, and associated attempts to formulate an inductive logic.

However, the move toward invalid arguments has some unenviable consequences. In short, since truth is no longer transmitted from the premises to the conclusion, neither is falsity retransmitted from the conclusion to the premises. The concept of knowledge is thus weakened so that knowledge can be false, and so knowledge, while still defined in contrast to conjecture, is no longer distinct from conjecture because knowledge is true while mere conjecture might be false. The difference between knowledge and conjecture is that to know something is to have an epistemic right to believe it, irrespective of whether it is actually true.

This whole situation is rather puzzling, since the problem which the idea of justified knowledge was intended to solve was how to identify and establish the truth. However, upon realising that no method of justification could achieve that end, philosophers have responded, not by abandoning the quest for justification, but by sidelining the search for truth!

The critical rationalist response is precisely the opposite: to abandon the quest for justification and continue to the search for the truth, and upon noting that both conjecture and knowledge may be either true or false, simply weakens the concept of knowledge until there is no distinction which remains. The preoccupation with whether or not we have an epistemic right to some belief is simply of no concern in this context, and people have a right to any belief they happen to choose if they think it is true. The only expectation is that those who call themselves rationalists or scientists, and are interested in learning from our mistakes, hold their beliefs open to criticism.

If all knowledge is conjecture then there is no need to check, confirm, or justify a conjecture before it can be elevated into the realm of knowledge. Therefore, argument can be conducted validly i.e. circularly, since there is no pretense that argument can justify anything, and the problem of justifying beliefs by invalid arguments which preoccupies many philosophers (the problem of induction is the most famous example) does not even arise as an issue, and certainly not as a problem which needs to be solved. In summary, the theory of conjectural knowledge amounts to little more than admitting our own fallibility, with the hopeful addition of a critical attitude.