(Click to enlarge painting of the uncontrolled senses—see description below)
"The modern civilization is to give freedom to sense satisfaction, because they cannot control. Just like you are riding on a horse, but the horse is not under your control, then you say, 'Let it go to hell, never mind.' This is the position. Because they cannot control the senses, they have taken this philosophy that liberating sense gratification is the ultimate goal of life. And the result is that they are going to hell. Adānta-gobhir viśatāṁ tamisraṁ punaḥ punaś carvita-carvaṇānām (SB 7.5.30). The problem is they cannot control the senses. Therefore their philosophical idea is that sense gratification is the ultimate goal of life. They are thinking, which will never be successful, that by advancement of material comforts they will be happy. Therefore the śāstra says impossible or very difficult or by a kind of hope which will never to be fulfilled. It was never successful in the past, it is not successful in the present, therefore in the future also it will never be successful."
(Srila Prabhupada Lecture, Los Angeles, September 15, 1972)
Pictured above (Bhagavad-gita 6.34): The chariot of the body. The five horses represent the five senses (tongue, eyes, ears, nose and skin). The reins, the driving instrument, symbolize the mind; the driver is the intelligence; and the passenger is the spirit soul.