Aristotle...on the pursuit of knowledge

From the beginning, until now, men have begun to philosophize because of wondering. At first they wondered about the extraordinary things near at hand, then they moved on from little things to raise questions regarding greater happenings, such as the phases of the moon, and of the sun and the stars, and concerning the origin of the universe. The man who is puzzled, and is wondering, is aware of his ignorance (wherefore the myth-lover is a philosopher after a fashion, for the myth is compounded of marvels). Since men philosophize to escape ignorance, it is clear that they seek scientific knowledge in order to know, and not for the sake of any practical end. The flow of events gives evidence of this fact. For when men have secured the necessities of life, and the things which contributed to leisure and amusement, they began to seek this kind of knowledge. Clearly then, it is not for some end other than itself that we such knowledge. As we call a man free when he exists for his own sake, and not for another, so this is the only one of the sciences that is free, for it alone exists for its own sake.

Metaphysics, 982b