philosophy...

[L_Hu]

Logic, mathematics, reason, and philosophy are all products of language. "Man acts as though he were the shaper and master of language, while in fact language remains the master of man. --Martin Heidegger". The world is merely what we think it is.

[Jafar]

Yes, actually, it does.

For one to thirst, one actually needs to need water, and be based on water, and well, all life is based on water.

Rephrased, yes, if a living being thirsts, then that implies the existance of water - not so much the thirst, but the living.

Let
Thirst = desires for water
(for clarity sake)

Then

If a living being posses a desire for water, then that implies the existence of water within the living being's mindset.

Transposed to another context gives us

If a living being posses a desire for 'meeting with an alien / being from outer space'.
then that implies the existence of an alien/being from outer space within the living being's mindset.
It doesn't necessary imply that this alien/being from outer space does in reality exist.

Salam / Peace

[drfazl]

Thirst or appetite is a God governed feel with no tangibility. If it is tangible then you can clearly explain the 'thirst' with a language and make one understand "O, this is thirst; now I know!"