There is nobody, I think, so senseless as to deny that there is pleasure in knowledge: and for the pleasures of sense, they have too many followers to let it be questioned whether men are taken with them or no. Now, let one man place his satisfaction in sensual pleasures, another in the delight of knowledge: though each of them cannot but confess, there is great pleasure in what the other pursues
 John Locke, An Essay Concerning Human Understanding (1689). copy citation

Context

“Happiness, under this view, every one constantly pursues, and desires what makes any part of it: other things, acknowledged to be good, he can look upon without desire, pass by, and be content without. There is nobody, I think, so senseless as to deny that there is pleasure in knowledge: and for the pleasures of sense, they have too many followers to let it be questioned whether men are taken with them or no. Now, let one man place his satisfaction in sensual pleasures, another in the delight of knowledge: though each of them cannot but confess, there is great pleasure in what the other pursues; yet, neither of them making the other’s delight a part of HIS happiness, their desires are not moved, but each is satisfied without what the other enjoys; and so his will is not determined to the pursuit of it.” source