on gratification of the eye...

Book X, 35

I must now speak of a different kind of temptation, more dangerous than these because it is more complicated. For in addition to our bodily appetites, which makes us along to gratify all our senses and our pleasures and lead to our ruin if we stay away from you by becoming their slaves, the mind is also subject to a certain propensity to use the sense of the body, not for self-indulgence of a physical kind, but for the satisfaction of its own inquisitiveness. This futile curiosity masquerades under the name of science and learning, and since it derives from our thirst for knowledge and sight is the principal sense by which knowledge is acquired, in the Scriptures it is called gratification of the eye. For although, correctly speaking, to see is the proper function of the eyes, we use the word of the other senses too, when we employ them to acquire knowledge. We do not say 'Hear how it glows', 'Smell how bright it is', 'Taste how it it shines', or "'Feel how it glitters', because these are all things which we say that we see. Yet we not only say 'See how it shines' when we are speaking of something which only the eye can perceive, but we also say 'See how loud it is', 'See how it smells', 'See how it taste', and 'See how hard it is'. So, as I said, sense-experience in general is called the lust of the eyes because, although the function of sight belongs primarily to the eyes, we apply it to the other organs of sense as well, by analogy, when they are used to discover any item of knowledge.

   We can easily distinguish between the motives of pleasure and curiosity. When the senses demand pleasure, they look for objects of visual beauty, harmonious sounds, fragrant perfumes, and things that are pleasant to the taste or soft to the touch. But when their motive is curiosity, they may look for just the reverse of these things, simply to put it to the proof, not for the sake of an unpleasant experience, but from a relish for investigation and discovery. What pleasure can there be in the sight of a mangled corpse, which can only horrify? Yet people will flock to see one lying on the ground, simply for the sensation of sorrow and horror that it gives them. They are even afraid that it may bring them nightmares, as though it were something that they had been forced to look at while they were awake or something to which they had been attracted by rumours of its beauty. The same is true of other senses, although it would be tedious to give further examples. It is to satisfy this unhealthy curiosity that freaks and prodigies are put on show in the theatre, and for the same reason men are led to investigate the secrets of nature, which are irrelevant to our lives, although such knowledge is of no value to them and they wish to gain it merely for the sake of knowing. It is curiosity, too, which causes men to turn to sorcery in the effort to obtain knowledge for the same perverted purpose. And it even invades our religion, for we put God to the test when we demand signs and wonders from him, not in the hope of salvation, but simply for the love of the experience.

[...]

My life is full of such faults, and my only hope is in your boundless mercy. For when our hearts become repositories piled high with such worthless stock as this, it is the cause of interruption and distraction from our prayers. And although, in your presence, the voices of our hearts are raised to your ear, all kinds of trivial thoughts break in and cut us off from the great act of prayer.

taken from St Augustine: Confessions of a Sinner, Translated by R.S. Pine-Coffin,
Penguin Books - Great Ideas Series, 2004)