I have had the same set of kitchen knives for over the last twenty years. The edge on these J.A. Henckels Four Star knives have held up remarkably well with little maintenance. They cut just as well today as they did when I first purchased them.
A dull knife is a poor tool. It is also dangerous to the user who is required to put more effort into the cutting. A sharp blade is efficient and makes quick work of the job, except if the knife is in the hands of an inexperienced user. They may cut more than what they intended.
A spear is not designed to cut. It is made to pierce. However, like the knife, in the hands of an untrained warrior or hunter, it is a poor weapon. Piercing everything but the target can have disastrous consequences.
Moving onto another tool that can both cut and pierce: the tongue. People generally welcome honest opinions. One should be able to freely express their feelings, opinions, and ideas. Yet, caution is needed here. Is this tool helping or harming its intended target? Spouting too much foolishness or having too little restraint will drive away any potential listeners.
The last tool is the flashlight. Oh yes, this is a valuable item to have in the dark. But if you shine it in the eyes of your companions, you will leave them dazed and unable to function. Their temporary blindness will be no help, and they will be wary the next time you hold the light.
The sage is sharp but does not cut, pointed but does not pierce, forthright but does not offend, bright but does not dazzle.Lao Tzu
The mind of the sage is the ultimate tool. It is a tool for both the master and the disciple. Yet, if it cuts, pierces, offends, or dazzles, its effectiveness is diminished. It will be reduced to a tool left in the shed because no one will want to be anywhere near it. If we want to be a sage, we must be sharp, pointed, forthright, and bright. We must be an effective tool to be fully utilized by all.