I am translating De numeris primis valde magnis by Leonhard Euler and I am somewhat puzzled by the following phrase on the second page: “per se praeclarissima videtur”.
Ac profecto natura numerorum primorum, cum ex iis modo tam admirabili omnes numeri componantur, per se praeclarissima videtur, et quo magis adhuc in proprietates, quibus sunt praeditae, penetrare licuit, eo magis haec doctrina digna censeri debet, cui excolendae plus operae tribuatur, quam nunc quidem plerumque fieri solet.
In the preceding paragraphs, Euler compares the search for the law of the progression of prime numbers to that of squaring the circle: they have little practical applications but the solving method itself (“methodus ipsa”) will no doubt be fruitful since great obstacles must be overcome. Therefore, the translation I would normally have chosen (“seems very clear by itself”) does not make sense.
And certainly the nature of prime numbers, since it is from them that all numbers are composed in such an admirable way, seems by itself very clear, etc.
“Illustrious” might be more appropriate but Euler already mentions a little earlier that the problem has a great reputation.