Even Philosophers make a leap of faith. In fact, they make many.
'Believe in yourself and go forth'
I have a small confession. The above quote is taken from the entrance to Victory Road, the long cavern I had to traverse in Pokemon Ruby (a computer game I played when I was 8 years old). The cavern is very long, with lots of complicated side routes. To enter was an act of faith that you could even get to the other side. To emerge out the other end was the result of chance as much as foresight and skill.
Philosophers take a leaf out of Pokemon Ruby. They make a whole host of Philosophical assumptions before they can even begin Philosophising - one of which is beliefs such as that you exist! After all, if you denied yours and others' existence when you started Philosophising, what sense would it make to build rational arguments on the basis that you had understood the last step? - After all, that past step was read and verified by a past you whom may not have existed!
Faith is something of a dirty work in 'rational discourse', largely because the rationalism of the Enlightenment has been so 'successful', that it has made anything which looks like opposition to these ideas a no-go zone for intellectuals.
Where to begin
Philosophers have to begin Philosophising somewhere, and when they do, they necessarily make assumptions about Philosophising being worthwhile in some way - it is only by Philosophising, after all, that we even deduce that Philosophy might be worthwhile! It clearly isn't immediately obvious that Philosophising is worthwhile - you might start reading Philosophy because it's interesting, but you might find maths, or sports or drawing equally interesting and fun.
It's a complex issue
Oh, and what if issues are infinitely complex?
We assume, that by Philosophising, we might reach 'the truth' (or at least most do).
This is an enormous leap of faith that:
a) Philosophical methods could achieve such a thing (and that such a thing exists!?)
b) That the questions have 'solutions' of 'limited complexity' (i.e. with our finite reasoning and steps we can reach an answer)
And on that bombshell...
Good luck to those of you who want to Philosophise. And to those of you who don't... fair enough I guess!
If you are curious about some of the intractable problems of Philosophy, you might be interested in:
The author for this article is the Sociable Solipsist, who studies at Cambridge University, UK. He enjoys doing Philosophy and Mathematics in his spare time, as well as writing flattering bios of himself in the third person