There are two ways to raise an army. The nation can draft its young into service, or it can use another form of conscription -- taxation -- to pay for a volunteer force.

Throughout most of our history, we have chosen the latter, more democratic approach. Nevertheless, sentiment and support for the draft appear to be rising on Capitol Hill.

Conscription has a long, if inglorious, history. The British Navy impressed 10,000 native-born Americans between 1793 and 1811, an outrage that led to the War of 1812. Throughout the 19th and well into the 20th century, immigrants by the millions sought the safety of these shores to keep their sons from being dragooned into the perenially warring armies of Europe. Until the Cold War, Americans regarded the draft as a last resort that could be justified only when the nation was in imminent peril.

The draft was abolished in 1973. To make the armed forces more attractive employers, Congress authorized higher pay, reenlistment bonuses and other incentives. Although the volunteer force does not work perfectly -- what in government does? -- it has performed far better than its critics prophesied.

In spite of predictions to the contrary, the quality of military recruits has improved since the draft ended. All prospective enlistees are assigned to one of five "mental categories" on the basis of aptitude tests. The law prohibits recruitment of the bottom 10 percent (Category V) but permits each service to draw up to 18 percent of its recruits from Category IV, which encompasses the 10th through 30th percentile. Over the past five years, the services have drawn only 7.4 percent of their recruits from Category IV.

The Army, which many thought would be unable to remain beneath the 18 percent ceiling, has confounded the pessimists. Only 11 percent of the Army's recruits have come from Category IV over the past five years.

More than a fourth of the Army is black; critics find that a cause for concern. The demise of the draft, however, appears to have had less to do with the rise of black enlistments than the sky-rocketing unemployment rate of black teen-age males. Relatively few young blacks have been able to find good jobs in the domestic economy.

This is not so much an Army "problem" as it is a reflection on the trades, businesses and professions of America. With these routes of upward mobility closed to many blacks, they have been turning in greater numbers to an institution that has long welcomed them. In the Army, many of them will gain additional education, useful job skills and a rewarding career.

When "equal opportunity" becomes a reality in the civilian economy, black representation in the Army will probably decline to a level close to their proportion of the population. To revive the draft now would only serve to limit the number of blacks who would be allowed to volunteer for the Army.

It costs more to recruit volunteers than it does to induct reluctant civilians, but the actual savings are small by Pentagon standards.

Rep. Les Aspin (D-Wis.), a member of the House Armed Services Committee, calculates that "the cost of the all-volunteer raise in 1977 came to $1.7 billion." That accounted for about a sixth of the boost in military pay; the lion's share (five-sixths) went to more senior military personnel.

If there were a new draft, the Department of Defense estimates it would save about $500 million in recruitment costs -- about $2 for every man, woman and child in America. The only way to save more money would be to slash military pay for all ranks, and Congress shows no inclination to take such a step.

In response to a congressional query, Secretary of Defense Harold Brown said recently that any new legislation to register young men for the draft should also be extended to include young women. As a matter of equity, it would be hard to argue against a unisex draft. American voters, however, might not take too kindly to the prospect of having their daughters as well as sons shipped off involuntarily to boot camp.

Few members of Congress are advocating that conscription be immediately revived; their present objective is the registration of 18-year-old males. With such a system in place, however, it would be a short step to actual inductions.

With some two million men and women currently in uniform, it is difficult to imagine the nation suddenly in need of millions more. Moreover, in this age of computers, registration would be much less a problem than the training and equipping of a massive influx of recruits. So, one could hardly plead logistical necessity in behalf of a so-called standby draft.

The real issue, of course, is money. The draft is a serious deprivation of liberty that can only be justified when the service of some must be conscripted to preserve the freedom of all. With the United States at peace, the case for a new draft rests primarily on how we will pay for our peacetime armed forces. The choice, in fact, is quite simple: We can draft dollars, or we can draft people.