The meaning and limits of philosophy; A Stroll with William James, by Jacques Barzun. New York: Harper & Row. 344 pp.

William James was surely the most likable of philosophers. Refreshingly unpretentious personally, he had a capacity for enjoying others even when he disagreed with them. No philosopher, suggests an admiring Jacques Barzun, could have been less dogmatic.

Barzun is a man of broad sympathies himself. Now retired after a distinguished career at Columbia University, he has devoted a lifetime to understanding the ideas which have shaped, changed, and shaken modern culture.

The prospect of a ''stroll'' with the two is engaging. William James was the older brother of the novelist Henry James and a figure of equal stature. He wrestled at the turn of the century with issues at the center of our existence today.

For Barzun, writing from the perspective of the 1980s, this book is a labor of love recording James's influence on his own values and convictions.

The older James was born in 1842 and wrote in an age when the concerns of philosophers were still universal concerns - the great questions of meaning and purpose and truth. Since then, as Barzun notes, the profession of philosophy has become more academic and its concerns more narrowly technical. Both the profession and the public have paid a price.

James combined a rigor that earned him the respect of his Harvard colleagues with a clarity that brought him a wider audience. He viewed metaphysics as essentially ''an unusually obstinate effort to think clearly.''

Thinking clearly in late 19th-century America meant thinking about a world which seemed to many uncomfortably insecure. For James, the comforts of conventional religion were no longer credible after Darwin. Unlike many of his peers, however, he rejected the materialistic dogmas often put forward in the name of physical science.

In his landmark text in psychology - the field in which he first gained recognition - James insisted that mind cannot be reduced to brain function. The distinction is crucial but largely overlooked in current neurological theories about intelligence.

In his best known philosophical works, James argued for Pragmatism, the precept that truth must be defined and tested in ''the daily moil of practice.'' No modern vision of truth - small t or capital T - can avoid the pragmatic test if it is to be taken seriously.

James preferred truth lower case. His emphasis was on experience ''as it is'' - concrete, particular, plural. In the rough-and-tumble of the 20th century, he realized, theologies or philosophies built on grand abstractions are built on sand. The course of history since James's day has made Barzun, for his part, even more gun-shy of absolutes and especially absolutisms.

This points to both a strength and a weakness in the book under review.

Like James, Barzun is a humane voice for tolerance and civilized values. He finds in James's thinking a basis, if not for faith, at least for decency.

Yet, in his enthusiasm, Barzun claims too much for his mentor. He disposes too easily of the ultimate questions - metaphysical questions - that James himself wrestled mightily with but finally put on hold. Philosophically, Pragmatism sought to redefine these questions rather than answer them. Its solutions, as James's colleague Charles S. Peirce saw, were often semantic rather than real.

The questions will not go away. For many in our own time, they lie on the heart like a stone that no will to believe can remove. For all his confidence in human powers, James also acknowledged that philosophy alone does not, cannot provide the spring of life and hope found in the heights and depths of spiritual experience.

Barzun, a warm-hearted humanist, does not set out to explore such peaks and valleys. But readers will find his stroll with James a vigorous walk on a hillside with many open vistas and clear views.