The phrase "doubtful nature" is correct and usable in written English.
It refers to something that is uncertain or unclear in its characteristics or qualities. It can be used in a variety of contexts, such as describing a person's personality, a situation, or a statement. Example: The suspect's alibi had a doubtful nature, as there were inconsistencies in his story and no witnesses to confirm his whereabouts.
At the time they argued that a widespread occurrence of protonated orthophosphates, which are known to serve as precursors of pyrophosphate, is doubtful in nature (cf. [15]), and that heating of such protonated phosphates in a closed system does not give polyphosphates because water cannot escape.
Although the coming round should, for example, bring easier access to rich markets for textiles from poorer countries, India was sufficiently doubtful about the nature of the promises on offer to hold out until the last minute, threatening to wreck the Doha agreement.The agenda for the new round is ambitious, not least because Europe wanted it that way.
It is doubtful whether in nature, control individuals from our experiment could have greater or equal fitness than selected progenies, but clearly a single severe perturbation (like a wildfire) would be more detrimental for the recruitment of domesticated, selected genotypes due to their immaturity (Keeley et al. 1999).
"Given that the tenant only will be away for 'up to' two weeks," Mr. Kassenoff said, "it is doubtful that the short-term nature of the arrangement would be sufficient to trigger an eviction".
Not long after their marriage, after they are settled into their routines and he has begun sleeping through the night, she frequently awakes and looks at him and "wonders about the nature of men, doubtful of the future," until "at last there came a night when she shook her husband awake and spoke of her own desire".
It's doubtful that anyone other than nature-show addicts will turn to "THE QUEEN OF TREES" (Sunday at 8 p.m. on Channel 13), a study of the symbiosis between the African sycamore fig and the tiny fig wasp.
Another reason to be doubtful of the Tamed Trump thesis is the nature of his mandate.
The refractory nature of the group means that it is doubtful that our observations are due to spontaneous remission.
It is always a doubtful idea to make room for four arms on a jacket when nature counts but two.
While mathematicians might be investigating the nature of abstract objects like numbers or sets, it seems more doubtful that legal philosophers are investigating the abstract object law.
