For I am well aware that scarcely a single point is discussed in this volume on which facts cannot be adduced, often apparently leading to conclusions directly opposite to those at which I have arrived. A fair result can be obtained only by fully stating and balancing the facts and arguments on both sides of each question; and this is here impossible.

要返工.
是没有篇幅写下所有的证据,不是没有.这段是为摘要写的序.他显然对自己很有信心,否则不会用"apparently".