Erectio Ergo Sum - 
Cartesian Dualism and the Mind/Penis Connection

Old School Aphrodisiacs 

The traditional concept of an "aphrodisiac" is consistent with a dualistic interpretation of the relationship between mind and body. An aphrodisiac is supposed to affect the mind, increasing sexual desire, and thus sexual performance. Lack of sexual desire is thought to be the cause of sexual dysfunction; fixing the mental problem is viewed as key to affecting the mere physical manifestation of that problem. The mind leads and the body follows.

Viagra only affects the body, not the mind, it cannot produce an erection without a mental state of sexual arousal. This shows how the mind and body are both intimately connected and at the same time very distinct entities, exploding traditionally rigid philosophical categories of dualism and materialism.

Modern Plumbing Fixes 

Not surprisingly, when modern science first succeeded in dealing with erectile problems, it took a materialistic body-first approach. Penis pump implants and direct penile injections worked completely independently of the mind. They produced erection without a mental state of arousal. With these methods, the penis is merely a piece of plumbing, disconnected from the mind. These methods work, of course, as you'd expect from scientific materialism. But they leave the mind out of the picture, offering an incomplete picture.

Viagra: You don't make me horny baby 

There are two common misconceptions about taking Viagra. First, many people think that it will make somehow turn you on, creating sexual desire out of thin air. However, Viagra has no direct psychological effect whatsoever. On the other extreme, many expect Viagra to produce an instant erection regardless of circumstance. In fact, Viagra won't produce an erection without some kind of sexual stimulation. In short, though it works only on the body with no psychological effect, it requires a mental state to have its physiological effect.

Viagra does, however, turn the slightest sexual stimulation into a raging hard-on. In a sense it amplifies your mental state. In a healthy individual, it can bring about an erection from stimuli that otherwise might have little effect. In the case of someone with erectile dysfunction, it allows the transformation of a mental state to physiological manifestation that otherwise would be short-circuited. But in either case, without the precondition of sexual arousal, no erection is forthcoming. 

The Feedback Loop

Of course, the simple fact of having an erection is likely to increase sexual interest. So, after taking Viagra, a slight sexual stimulus can produce an erection, and that erection can then in turn bring about more sexual thoughts and interest, thus maintaining or even enhancing that erection. The mental affects the physical, and then the physical in turn influences the mental. 

This feedback loop offers a prime example of the intricate links between the mind and body. Though there's a real distinction between the two, one can't be separated from the other. There's a continuous ebb and flow of thought and action. There is no body without the mind and vice versa. We have both an embodied mind and mental processes that transcend our mere physicality. That is just one the profound lessons we can learn from Viagra.