What is the difference between 楽しい, 愉しい, and 娯しい?

Question

Recently I've been trying to understand the difference in nuance between the words 楽しい, 愉{たの}しい, and 娯{たの}しい, but I'm still confused after reading a few different explanations on chiebukuro and other sites, some of which conflicted with each other.

Firstly, the two main differences between these apart from nuance are:

• 楽{たの}しい is a 常用 reading for 楽, while 愉{たの}しい, and 娯{たの}しい are non-常用 readings for 愉 and 娯.
• 楽しい is almost always used, 愉しい is used once in a while, and 娯しい is used rarely.

Now, for the nuances, I've read and understood (possibly mistakenly) that:

• [Source 1]: 楽しい is “fun”, 愉しい is “fun without feeling even an inch of discomfort/displeasure/with no reserves”.
• [Source 2]: 楽しい is “fun”, 愉しい has a nuance of “fun which you enjoy with your whole body (?)”, and 娯しい is “fun, but funnier than 楽しい”. The other answer says 愉しい is “fun” with a niche nuance, as in enjoying a classical car collection.

^{(It also mentions 悦{たの}しい (which seems to be pretty much never used), claiming that it carries a connotation of “pathological” fun)}

• [Source 3]: 楽しい is “fun”, and 愉しい (from what I understand) is more subjective (e.g. one finds something to be fun), and seems to have a connection to Buddhism.
• Finally, I also found someone claim that 愉しい is “fun, but funnier than 楽しい”, similarly to 娯しい in the second bullet point above.

So... What really is the difference in nuance between these?

Also, is this nuance understood and respected by most Japanese people in writing, e.g. novels? Or does the typical native Japanese reader perhaps feel a bit like "愉しい is funnier than 楽しい, though I don't know what 娯しい means"?

Answer 1

The short answer is "愉しい and 娯しい are alternative spellings only for novelists, copywriters and lyricists. You probably should not use them."

While there are many word pairs whose difference is imortant for ordinary people (e.g., 速い vs 早い; 勤める vs 努める; 泣く vs 鳴く), there are also many spellings that are used only in aesthetic writings to add some "flavor".

愉しい belongs to the latter category. I am not surprised that everyone has a disparate explanation for it. If you ask me, there is no fundamental difference in meaning in the first place! The only "difference" is that it feels somewhat literary and/or profound simply because it's uncommon. Perhaps 愉しむ tends to be more commonly used in the contexts of "classy" hobbies (e.g., watch, whiskey, haiku), especially in ads, but that does not mean 愉しむ has a special meaning by itself. If you are not a novelist but use such kanji often in SNS, people might think you are odd. Personally, although I can easily read 愉しい, I never use it when I write something.

As for 娯しい, it's simply so rare that I can't even read it without furigana. Rather than worrying about or memorizing its nuance, it's better to think about why such an unusual spelling is used.

See also: Why do authors choose to use obscure/old ways to write words?