This quote uses vivid imagery to highlight the limitations of surface-level learning. "Index-learning" refers to the practice of merely skimming through the contents or the index of a book without delving deeper into the material. The phrase "turns no student pale" suggests that this type of learning does not require much effort or cause any stress.
The second part of the quote, "Yet holds the eel of science by the tail!" refers to the slippery and elusive nature of knowledge. Just as it is almost impossible to hold onto a slippery eel, grasping the depth and breadth of a subject like science can be challenging. Holding the eel by the tail suggests a superficial or insecure grip on knowledge. The student may have a hold on the subject, but it’s a precarious one that could easily slip away.
In today’s fast-paced, information-saturated world, the quote’s message is even more relevant. The internet, for example, offers a wealth of information at our fingertips, making it easy to skim through information without truly understanding it. This can lead to a false sense of knowledge or expertise.
In terms of personal development, this quote suggests the importance of deep, focused learning. Rather than trying to learn a little about a lot, it may be more beneficial to learn a lot about a little. This involves immersing oneself in a subject, questioning, exploring different viewpoints, and seeking to understand the underlying principles or concepts. This kind of learning is likely to be more rewarding and effective in the long run, allowing for a firm grasp on knowledge, rather than just holding onto the ‘tail’ of it.