That is a pretty powerful statement to make. It seems to indicate that every human being lives with a "death wish". But what does it mean that the "inclination of a person... seeks to kill him?"
Referring back to the verses pertaining to the creation of mankind, there are two essential components mentioned, namely, a Divine soul (also referred to as the "image of God"), and dust of the earth. After the mistake of eating from the Tree of Knowledge of Good and Evil, the Torah states:
"... because from dust you were taken and to the dust you shall return."(Genesis 3:19) This statement refers to the "curse" of death on mankind for eating from the forbidden tree. But perhaps it describes more than just the end result of life outside of the Garden of Eden; perhaps it is a warning of the new challenge in life, an allusion to a new "natural" leaning towards death. Is it to this that the above Talmudic statement refers?
What this means is that the physical element of man is "naturally" drawn back to its source, like iron filings are drawn to a magnet. Itís not that the body maliciously tries to end a personís life, itís just that it wants to go "home" and unfortunately, that results in death for the individual. And it would succeed at killing the person if it wasnít for the other aspect of being human.
Human beings, unlike other living beings in this world have a Divine soul. Its source is God Himself, the Torah teaches, and just as the body yearns to return to the earth from whence it came, so too the soul yearns to return to its Divine source.
Thus within every single individual there is tremendous tension between two opposite inclinations: one to live (the soul is a life force) and one to die. Victory of one over the other either results in death (suicide) or perfected living (righteousness).
In the ongoing war between the drive to live and the drive to die, complete victory is not necessarily possible for either side. So each side has to be content with fighting and winning battles only.
For example, unable to motivate suicide, the body settles for partial suicide: wasting time or needlessly pursuing comfort by unnecessarily expending thought, energy, and time. Unable to motivate a drive for spiritual perfection, the soul tries for moments of righteousness, such as acts of kindness. However, the result of only isolated victories for the soul is mediocrity.
Happiness is not the result of crushing the "enemy." As the midrash pointed out, the evil inclination is necessary just for survival alone. Then what is the goal of the battle?
Rather than compare the struggle between the evil inclination and the good inclination to two warring enemies, compare it instead to a mother and a child in a supermarket.
The mother takes the child shopping to accompany her, that is, to keep her company and not to be a nuisance. But when the shopping cart swings past the candy section, bells go off in the childís ears and he cries out, "I WANT THAT!"
The mother, very often, says "No," to which the child responds in force with a tantrum that attracts the attention of passers-by for miles around. The mother, fed up and embarrassed, promises herself that she will never again bring her child shopping!
Basically, there are four solutions to the problem. The first solution is to hit the child and scare it into submission. But often that is not a positive solution at all.
The second solution is to capitulate and buy your screaming child the candy. But that response is often seen as a weakness in the parent, and opens the parent up to future manipulation.
The third option is to leave the child outside the store, and not bring him back next time. But that option too is less than ideal. What is the ideal solution?
Imagine telling the child, "Look, I know youíre disappointed, and Iím not turning your request down to punish you. Itís just that Iím short of money, and we need real food. Besides, itís almost dinner time and the candy will ruin your appetite, not to mention cause a cavity."
Wouldnít it be great if the child responded, "Gee mom, it didnít occur to me that thatís what was going through your mind. Had I known that I never would have had a tantrum. In the future, Iíll be sure to discuss the matter with you before I make such potentially silly requests."
Of course, most children will not respond that way to their rejected request for candy; theyíre not mature enough. The evil inclination also has difficulty grasping higher concepts quickly. So, like a smart parent with a driven child, one has to find a way to channel the drive of the evil inclination.
Returning back to the mother-child analogy, the clever mother will find a way to "buy time" with the child. Flat-out refusal of the childís request will spark a tantrum, but complete capitulation to the child could result in a spoiled child.
There is no singular solution that can be applied to every child, but every mother has to look into the heart of her child and find a solution that can both satisfy the child and herself.
Likewise, there is a way to convince the evil inclination that behaving nobly will result in more pleasure than acting destructively. This is the job of the intelligent individual to work out. There are few greater joys than when a child happily works with the parent; there is no greater joy than when the energies of the evil inclination are channeled in a positive direction.
This is to large degree the source of the pleasure of the Shabbat. Shabbat is a day during which we cease from specific types of creative work, but also a day on which we are supposed to eat good foods and do meaningful activities. In this way, both the evil inclination and the good inclination are working towards the same goal: an enjoyable Shabbat, and the result is personal growth.
This is only a beginning to understanding the dynamics of the two inclinations of the human being, and the challenge of life. But it is enough information to assemble a more sophisticated perspective on the equation of life:
We are now finally able to ask in earnest, what is the "Y Factor?"
(Good Inclination Maximum
+ Free Will + "Y" = Evil Inclination)