有言在先.怎么翻译？

Warning

但是，尽管有言在先“本书通篇以科学为要，兼容并包而（对各门学科）未加平衡”，物理学还是被忽略了。
But despite a warning that “there is a good deal of science in the book, as much as can be accommodated without the machinery of equations”, the story neglects the physics.

we have promised