Can I replace 'perspicacious' by 'astute' here?

Question

When I searched 'perspicacious' in google or bing, pictures of Albert Einstein and Sherlock Holmes turned up. So, it seems that we can use 'perspicacious' to describe them as in the following dialogs, right?

1. Tom: Einstein discovered the theory of relativity.

   Friend: He's such a perspicacious scientist.

2. Jack: Did you ever read A Study in Scarlet?

   Friend: Yeah, Holmes' so perspicacious.

Can I replace the 'perspicacious' above by 'astute'?

According to Merriam-Webster, astute means

having or showing shrewdness and an ability to notice and understand things clearly: mentally sharp or clever.

One of the example uses of astute there is

an astute observer.

So, it seems reasonable to describe Einstein and Holmes as astute. After all, they are both good observers, one of science and the other crime scene. What bothers me is, in Cambridge Dictionary, astute means

able to understand a situation quickly and see how to take advantage of it.

An observer of the stock market or politics may benefit from his/her astute observation and take advantage of a situation, but how can a scientist or detective 'take advantage of it'?

Is it natural to use 'astute' to describe a scientist or detective?

Answer 1

As several commenters have pointed out, the word astute is generally associated (by dictionaries including Merriam, Wiktionary, and the OED) with craftiness or cunning. However, I would argue that this is a somewhat traditional reading of the word; to my ear at least the word has a positive connotation (evoking accuracy, thorough incisiveness), especially when directly modifying some noun, e.g. astute observer, astute analysis, astute investigator.

As to if perspicacious is appropriate in the contexts you provide, I would join with @Michael_Harvey in saying that perspicacious applies much more to a detective than to a scientist. Good scientists are good observers of the natural world, but they are also diligent, meticulous, and various other qualities--to be sharp-eyed is not necessarily to be a good scientist. On the other hand, good detectives are sharp-eyed observers and sharp-eyed observers make good detectives, basically by definition. In the case of Einstein, the word perspicacious may not a particularly good choice: he didn't observe the theory of relativity, he formulated it.

In both contexts, astute works, but it may not be the best choice: a reader, if they are so inclined, might understand astute detective as implying that the detective is somewhat corrupt, or an astute scientist as motivated by personal gain, perhaps to the detriment of others. But I would like to point out that it's easy to find examples of these (or similar) phrases being used clearly absent of any such implication:

In an obituary for a dead police officer:

He had a great way with people but he was also a very astute policeman and he nurtured a lot of talented officers - he mentored a lot of people and was always generous with his advice and time. 1

In a description of a dead physician:

Andreas Roland Grüntzig (1939-1985) was an accomplished clinician and an astute scientist. He was also a practical man endowed with dexterity, smartness, and common sense.2

Finally, I'd like to add that the word perspicacious is quite rare. If you use it casual conversation [outside @Michael_Harvey's household (: ] it is very likely you won't be understood. I just polled three of my English major friends and none of them knew the word. Google Ngram lists it as about 20x less common tham astute (though the OED somehow has it in band 4, alongside rodeo and overhang)