There is really nothing wrong with being ignorant and confused. That can be fixed. The problem is when ignorant fools try to act like all knowing sages. I have been there and done that. ~~ me
Most of us had the thought, 'If I only knew then what I know now.'
Of course the meaning of that thought changes over time. Lately, it occurred to me that is a probably a good thing I did not know back then what I know now. Sometimes, a certain amount of naive ignorance can be healthy. Too much knowledge, in the wrong hands, brains, or minds, can be dangerous.
Where is the Life we have lost in living? Where is the wisdom we have lost in knowledge? Where is the knowledge we have lost in information? ~~ T. S. Elliot
Words might mean things, but those meanings change over time and with context. In the above quote, I think Eliot was using the word 'knowledge' in the sense of technical information and the word 'wisdom' in the sense of having the practical skill to apply it. I think this is the most common contemporary take on the difference between knowledge and wisdom.
Knowledge is the awareness and understanding of facts, truths or information gained. Wisdom is the ability to apply knowledge. ~~ random quotation from the Internet
In this sense, wisdom implies something rather subjective, whereas knowledge is more objective,.While that seems to be the common contemporary understanding; it is not the original sense of those words. I am tempted to say that the meanings have been reversed, but that is not quite correct. It is far more nuanced than that. Let's look at some sanskrit cognates from Buddhism:
Vidya (pali vijja, chinese 明): This is a rough cognate of many English words; including wisdom, vision, wit, wiccan, and wizard. The root, vid, means both 'to see' and 'to know.' The suffix -ya or -aya can, among other things, make a verb into a noun. It is a cognate of -ia /-ion and -y/-ity. Vision is almost a direct cognate, but it does not work as a translation of vidya in any contemporary sense. A better translation of vidya would be wisdom in the following senses:
1 a: accumulated philosophic or scientific learning.
1b. generally accepted belief
3. the teachings of the ancient wise men~~ www.merriam-webster.com/dictionary/wisdom
Note in those senses, wisdom refers to objective fact, or accurate information. As such, some have suggested 'science' as modern translation of vidya. Others have suggested 'lore.' Still others cop out and say that either wisdom or knowledge can be used. I am tempted to say 'recorded wisdom', but the ancients did not write it down, it was transmitted orally, usually via verses or stanzas memorized by rote.
Of course, these days, oral transmissions imply arcane teachings. However, originally, both public / exoteric and private / esoteric teachings were transmitted orally. Moreover, vidya includes both exoteric amd esoteric teachings. For now, I am going with 'Objective Wisdom' -- teachings that are accepted as axiomatic. By the way, the opposite of vidya, avidya, is probably best translated as nescience.
Jnana (pali nnana, chinese 智): This is a rough cognate of the Greek gnosis and the English word knowledge. It is composed of the verbal root jna; to know, and the suffix -na; - ing. So it literally means knowing, but is used as gerund, an action noun, rather than a verb or adjective. Some say it is just a synonym of vidya; which is probably true in non-technical usage. However, as a technical term it means subjective comprehension or knowledge, having a direct and accurate grasp of vidya. I am going with "Subjective Knowledge" as the best translation for now.
The opposite of jnana is ajnana and means ignorance in the sense of simply 'not knowing.' On the other hand, Avidya would be thinking something is true when it is false.
Prajna (pali panna, chinese 慧 ): This consists of the prefix pra and the verbal root jna. The prefix pra- can mean for, for each, before and so on. It is a cognate of pro-, per-, or pre. In prajna it appears to means for in the sense of purpose.
Prajna is commonly mistranslated as wisdom and commonly mistaken to mean practical wisdom. Discernment is a better translation. I am going with intelligence in the sense of the ability to acquire knowledge. The opposite of prajna is moha which means confusion; stupidity; foolishness; delusion ...
One thing, I am not saying that so-called practical wisdom is not prajna; it just that 'street smarts' is not the only kind of intelligence.
Some people are good at samatha; while others are good at vipassana, but very few are good at both. ~~ the Buddha {paraphrased}.
Shamatha (pali samatha, chinese 止 ): This does not mean stopping, calming, or tranquility, and certainly does not mean concentration. It is, however, developed by a kind of concentration that involves a sort od slowing down, controlling stilling, or quieting -- but not stopping -- the mind.
Let's look at the etymology. Shama means to cool down or pacify. The suffix -tha means to remain or abide. As such, 'calm abiding' is a good, very literal translation.
Buddhism teaches a method to develop samatha. It is called appana samadhi (fixed or absorbed concentration) or dhyana {absorbed thinking}. There are two kinds of this. Rupa dhyana {object absorption} and arupa {object-less, abstract, or conceptual absorption}.
Vipashyana (pali vipassana 観 ): This word is generally translated as insight, observation, introspection, or clear seeing. All of those are accurate and literal translations. I think what it gets at is close to what we might call common sense, practical wisdom, intuitiveness, cleverness, or being street-smart. One caveat though, we are not talking about slyness or being slick. Vipassana is a wholesome state in which one has heightened powers of observation. Expansive awareness might be a decent translation.
Let's look at the etymology. Passa comes from the verbal root pas, yet another word that can mean "to see" or "to know." Right now, I take it to mean "to observe." Passana, or seeing, is another gerund, an action noun meaning sight or observation . The prefix vi- is the same as the English dis- used as an intensifier with a positive valence, as in the sense used in disgruntled. While this use of vi-/dis is rare in English, it is fairly common in Indic religious words, such as vishuddha. At any rate, adding vi- to passana is like adding in- to sight; hence insight; "the power or act of seeing into a situation."