answer:If you are talking about firm ground, then no, as the Standard Model was in place as a theory and had strong experimental backing by about 1978 (Tao was published in ‘75). IIRC Capra was involved with the “analytic S-matrix” and “nuclear bootstrap” theoretical movements, which turned out to be (for the most part) dead ends. He does not seem to have recognized this… “The Tao of Physics was completed in December 1974, and the implications of the November Revolution one month earlier that led to the dramatic confirmations of the standard-model quantum field theory clearly had not sunk in for Capra (like many others at that time). What is harder to understand is that the book has now gone through several editions, and in each of them Capra has left intact the now out-of-date physics, including new forewords and afterwords that with a straight face deny what has happened. The foreword to the second edition of 1983 claims, “It has been very gratifying for me that none of these recent developments has invalidated anything I wrote seven years ago. In fact, most of them were anticipated in the original edition,” a statement far from any relation to the reality that in 1983 the standard model was nearly universally accepted in the physics community, and the bootstrap theory was a dead idea… Even now, Capra’s book, with its nutty denials of what has happened in particle theory, can be found selling well at every major bookstore. It has been joined by some other books on the same topic, most notably Gary Zukav’s The Dancing Wu-Li Masters. The bootstrap philosophy, despite its complete failure as a physical theory, lives on as part of an embarrassing New Age cult, with its followers refusing to acknowledge what has happened.” - Peter Woit (see also: Lost Causes…)