go into the principle of;probe into the essence of things;pursue to the very source of a learning ❍ 你学习时不应囫囵吞枣，而应～。You can’t just learn without understanding,but you should go into the principle of what you’ve learned. ❍ 致知在格物，格物而后知至。(礼记·大学》)Such extension of knowledge lay in the investigation of things. Things being investigated,knowledge became complete.