"他解为" can be translated into English as "he interpreted it as" or "he explained it as", depending on the specific context.
If referring to interpreting or explaining a concept, theory, or text, "he interpreted it as" would be more appropriate.
If emphasizing the act of providing an explanation or definition, "he explained it as" could also be used.
For example:
"他解为这是一个哲学问题" could be translated as "He interpreted it as a philosophical question."
"他解为这个公式的意思是..." could be translated as "He explained it as meaning that the formula..."