branch out (/reason/comprehend) by analogy; draw parallels from inference; grasp a typical example and you will grasp the whole category; single out one thing and bring out its interrelationships
? 因此而曉悟了知的，豈只是一種植物的生活史； 生命的秘奧，萬物的消息，也將觸類而旁通。(葉圣陶《倪煥之》137) Now what they learn from all this is not just the life-history of one species of plant:they can branch out by analogy into the whole mystery of life and a study of all living things.
觸類旁通
reason(or comprehend)by analogy;single out one thing and bring out its interrelationships;grasp a typical example and master the whole category
觸類旁通chù lèi pánɡ tōnɡ
旁通：互相貫通。指懂得或掌握了某一事物的知識，就可以推知同類的其他事物。reason by analogy, draw parallels from inference, branch out by analogy