The phrase "a mere hypothesis" is correct and usable in written English.
It can be used when discussing a theory or idea that is not yet proven or is considered to be of little significance.
Example: "While the results are intriguing, they are based on a mere hypothesis and require further investigation."
Alternatives: "just a theory" or "simply a conjecture".
New scientific knowledge has led us to realize that the theory of evolution is no longer a mere hypothesis.
Pope John Paul II, in an address to the Pontifical Academy of Sciences on October 22 , 1996 deplored interpreting the Bible's texts as scientific statements rather than religious teachings, adding: New scientific knowledge has led us to realize that the theory of evolution is no longer a mere hypothesis.
Yet Church's thesis is a mere hypothesis, and a hypothesis that cannot be proven true.
Until then, it remains a mere hypothesis that the principle of human freedom, for all of its practical certainty, is also the proper starting point for a transcendental account of objective experience.
Note that the fusion along the axon is not a mere hypothesis: it takes place abundantly in immature axons.
9 33 While this remains a mere hypothesis, not practically proven to be effective, its theoretical application has been tested and recommended for some surgeries.
The creators of these guidelines emphasize that it is not a mere theoretical hypothesis, but it draws inspiration from similar experiences which are already well tested in the real world: it is analogous to existing regulatory regimes, such as those for quarantine regulations for plant or animal pests.
Accordingly, we submit that the utility of the present results is not limited to mere hypothesis generation, as is typically a major weakness of retrospective analyses.
This was mere hypothesis, since Gaskell had no contact with Brontë after her marriage.
That was already old news in the 18th century, when thinkers such as the philosopher-chemist Joseph Priestley took it to be more than mere hypothesis.
But the Earth is hit by meteorites all the time, so they could be "contamination" from smaller impacts.At the moment, this idea is mere hypothesis.
