Blasphemy specifically refers to the verbal desecration or cursing of G-ds Name. But many related commandments deal with the sanctification of His Name, the treatment of holy objects, and other aspects of reverence for holiness. In essence, then, what is the definition of blasphemy?
While the idolater rejects Truth itself, the blasphemer does not. The very fact that the blasphemer tries to injure G-d (G-d forbid!) is itself the clearest possible acknowledgement of G-ds existence. The blasphemer is not ignorant or misled; he knows the Truth and chooses to rebel against it by opposing the introduction of holiness into the physical world. He is an antinomian, wishing to keep the spiritual and physical divided from one another.
The opposite of a blasphemer or profaner of G-ds Name is one who yearns for G-dliness to transform the creation, stands in awe of G-ds magnificence and inescapable judgment, reveres sanctity established in space and time, and stands ready to sanctify G-ds Name even with martyrdom, if appropriate.
We therefore classify here, in addition to clearly blasphemy-related issues, all commandments related to reverence, ceremonial observance, and holy items, leaving commandments regulating social affairs to other categories.