It was the promise of accuracy that drew me to philosophy. The promise of being able to look into something as messy as an argument and identify clear winners and losers. Ironically it was a scientist, not a philosopher, who got me hooked. I remember reading the God Delusion as a teen and being floored by Richard Dawkins as he reasoned his way to concrete conclusions on abstract topics like God and morality. For a long time this was what I thought philosophy actually delivered: a systematic grilling of suppositions that removed fuzziness from elusive subjects via cold logical necessity.
Of course neither philosophy nor logic operate in the way my young self envisioned them. Noting that the premises "A" and "A therefore B" provide you with the conclusion "B" is all very well, but working in real time to demonstrate the soundness of even a simple modus ponens can be difficult. The problem stems from different people's propensity to entertain selected premises with varying levels of enthusiasm. Not only that but people, philosophers especially, often end up arguing about the appropriateness of various linguistic conventions within which a premise might be expressed.
This observation is mildly troubling to anyone of a similar disposition to my younger quasi-neo-positivist self. If arguments are to be disputed effectively in a dialogue of pure logic then the participants need to share the appropriate premises. The sheer extent to which philosophers fail to share premises, including fundamental ones like those governing concept identity, somewhat undercuts the idea that philosophy is an activity of just applying logic and coming to a conclusion.
It is important to note however that this isn't a problem for the broader application of logic within philosophy. Instead it is a problem for notions of philosophical truth attempting to approximate "certain truth". Cartesian demons aside, there is a distinction between scientific truth and philosophical truth. While the outer rims of scientific inquiry are uncertain places science does provide us with facts like "water at sea level boils when it hits 100 degrees Celsius"; these are things that philosophy doesn't provide. Even the most instrumental of fields, applied ethics, rarely confronts us with anything like a philosophical consensus out of which could emerge a "fact".
This wide zone of disagreement is a product of philosophical arguments being dependent on premises which are themselves nestled into wider networks of related philosophical arguments which in turn are nestled in even wider networks... ad infinitum... Or maybe not quite ad infinitum, but these chains are long enough and often so complex that tracing them may as well be an infinite endeavour. So, where does this leave philosophers?
Well, assuming that we don't have time to sit debating the truthfulness of every connected premise in a given argument then we will just have to assume certain premises. Of course which premises we question and which we accept are determined by our aforementioned predilections. Furthermore while the arena of debate often acts as an aid forcing us to defend premises that we would otherwise assume to be true, it's efficacy is limited: opponents in a debate only point us towards premises that they would question, not necessarily the premises we should question.
In light of this I don't think we can position philosophy as the provider of linearly accrued capital K "Knowledge". Philosophers cannot snatch certainty from the jaws of the abstract. Yet maybe they can offer something that is more contingent and perhaps just as illuminating. Philosophical debates rarely end, but they are often developed and deepened. A more realistic goal for philosophy may just be to properly delineate the gaps in our knowledge and provide a selection of placeholders in lieu of definite answers.