Capable of being doubted; susceptible of being questioned.
The word "dubitable" is correct and usable in written English. You can use it to describe something that is doubtful or open to question. For example, "The authenticity of the document was dubitable.".
The way President Trump himself frequently tweets dubitable information has, at least, further devalued the entire idea of substantiation, if not knowledge itself.
The investigator determines whether a proposition is dubitable by attempting to construct a possible scenario under which it is false.
However, besides propositions per se nota there are certain mechanisms through which originally dubitable propositions can come to be evident in the third degree, thereby necessitating assent and causing a truly evident judgment.
Wodeham's conclusion is decidedly in favor of the latter; namely, in order for a previously dubitable proposition to be elevated to the third degree of evidence, whereby the intellect is necessitated to assent, it must acquire that evidence from the force of the syllogism as whole.
In this case reverse the process, work backwards, and try to deduce your original conjecture via the inverse route from the indubitable truth to the dubitable conjecture.
But this solution has been found dubitable by many commentators.
When they are delivered by authority they are dubitable, confused, and lack self-evidence.
Being a terminologist, I care about word choice. Ludwig simply helps me pick the best words for any translation. Five stars!
Maria Pia Montoro
Terminologist and Q/A Analyst @ Translation Centre for the Bodies of the European Union