(FORTUNE Magazine) – Mention women in management and the instant association in the minds of most men (and women) is: Women have babies. The conclusion follows naturally that women can't be counted on to make a full-time, open-ended commitment to their careers. The truth of the matter is quite different. Women are the bearers and, traditionally, the sole nurturers of children, and they are more likely than men to switch between careers and family. But they are no longer a homogeneous group. Some still support their husbands' careers, tending the hearth and raising the children. Others struggle to balance their own careers with family responsibilities. And a significant number are determined to reach the top of their field. Many of the most gifted and able leaders of the future will be women to whom career is primary, women who are ready to make the same trade-offs that male leaders have traditionally made. Companies that do not spot and groom these women are shortsighted. There has always been a paucity of individuals endowed with extraordinary intelligence, creativity, motivation, and the ability to get things done. Despite the overabundance of the baby-boom generation, this shortage persists. The demand for intelligence is greater in the complex service economy than it was in the manufacturing economy, and increasing numbers of young people want work that leaves more time for other interests. Within a few years, as the effects of an aging baby boom are felt, the talent of women will become indispensable. Companies that start now to develop the leadership potential of women will have a competitive edge in recruiting and keeping the best and brightest of them. Seeking out female leaders is not the same as counting heads and moving women up to meet affirmative action goals. Quotas and timetables, which were productive when women were just beginning to enter management, do not ensure quality or motivation. Both business and women will lose if women who do not have the aptitude and drive to succeed are promoted to top levels. The challenge is not an easy one. It goes against the grain of most senior executives to encourage and welcome the women, so unlike their wives, who put career before marriage and rearing children. Talent in women is not difficult to recognize, but the very qualities that bespeak motivation -- determination, drive, aggressiveness, singlemindedness -- still tend to provoke discomfort and uncertainty even among male executives who have decided they should be developing female leaders. Most difficult is coming to terms with the possibility that a promising, hard-driving, goal-oriented woman may nonetheless in the course of life change her priorities. She may take a leave to have a child, and discover the joy of parenting just when she planned to turn over the care of her infant to someone else. Given a man and a woman of equal abilities and motivation, investing in the woman is undeniably riskier. Attrition among women stars will be greater -- for the present, significantly greater -- than among men stars. Why, then, should corporations take the time to groom women for top jobs if a smaller proportion of them can be relied on to put their careers above all else? -- So that the company can capture the best people for leadership positions. Skimming the cream from both the male and female barrels, rather than digging deeper into the male barrel, pays off in quality gains that far outweigh the larger investment the company must make in women. -- So that the C.E.O. will gain critical early experience in communicating and working with these superbly capable women, with whom he is currently apt to be ill at ease. -- So that there will be female role models for younger high-potential women. -- So that the ablest women coming out of colleges and graduate schools will see that the company gives women the opportunity to move up to the top. -- So that the company's customers -- many of them females or males concerned with equal opportunity -- will view it positively. -- So that women, on whom half of all training dollars are spent, do not feel stifled, scale back their aspirations, and so fail to amortize the investment made in their training and experience. -- So that all ranks of management can be filled with stronger executives. Too often the middle level of the pyramid is composed solely of those who tried to make it to the top and failed. That group can be upgraded if it also includes the women -- and some men -- who have the skills to achieve the highest levels but have consciously put a lid on their career aspirations to spend more time with their families or pursue other interests. MUCH OF THE SAME EFFECT will be seen in the broad lower level of the pyramid. Jobs here do not require extraordinary ability or single-mindedness. There is room for managers who want to avoid the heavy demands on time that come with work in the higher levels. Employers who recognize this can provide inducements -- maternity leaves, for example, or child-care support systems -- that most women and many men want and need. Such flexibility can make the difference between getting employees who simply put in their hours and those who perform with enthusiasm and effectiveness. At all levels of the organization, cultivating the best of the women available means getting motivated people who are pursuing their dreams, whether those encompass balancing many aspects of life or driving hard for the top.