In this week's Parsha, we learn about an individual who wishes to be involved in a special relationship with Hashem. He thus imposes upon himself certain extreme restrictions, such as refraining from consumption of wine or grape products. He also does not cut his hair and may not come into contact with a dead body. Becoming a Nazir is in many ways an act of extremism, and the question may therefore be asked whether the Torah is encouraging one to become a Nazir or merely allowing it. Is becoming a Nazir fundamentally something good or something not so good?
Perhaps surprisingly, Chazal are not really as clear about this as one might expect them to be. In fact, there seem to be some contradictory ideas. For example, our Parsha tells us that when one has finished his period of time as a Nazir, he must bring a Korban Chatas (במדבר ו:י"ד). This would imply that being a Nazir involves the commission of some sin, because a Korban Chatas is brought to atone for a sin. The Ramban, however, explains this Posuk as teaching that the sin here is the person's decision to stop being a Nazir, because as a Nazir he is closer to Hashem. The Gemara in Sotah (דף ב.) also seems to recommend that one become a Nazir under certain conditions, but the Yerushalmi in Nedarim (פרק ט' הלכה א', דף כ"ט.) objects to someone who takes on extra prohibitions not required by the Torah. The Yerushalmi in Berachos (פרק ב' הלכה ט', דף כ"א.) calls someone who does something he's exempt from doing a fool; the Rambam (פרק ג' מהל' דעות הלכה א') also recommends that one not act in an extreme fashion and understands that the Nazir has indeed sinned by taking on extra prohibitions.
The answer to these contradictions and to our question seems to be that it depends on the specific situation and the person's motivation. In general, Judaism does not encourage extremism; the Torah is a guide as to how to live in this world. The observant Jew is not meant to go live on a mountain-top completely isolated from society; he is meant to function in and interact within society. Kedushah is attained when one is able to function normally in the world and still adhere to the Torah and the Mitzvos. At certain times, however, certain people may find that almost impossible. Rather than compromise on Torah and Mitzvos, one may then decide to accept more extreme restrictions and, if necessary, cut himself off even more from his surroundings. If his motivation is correct and he needs these extra precautions to maintain his level of Kedushah, he may and should become a Nazir. If he is confident he can remain sanctified without doing so, however, it is perhaps better not to become a Nazir.