Not at all.  An assumption is &quot;a thing that is accepted as true or as certain to happen, without proof&quot; [1].  The goal of science is minimize assumptions and maximize knowledge (justified, true belief) [2].<p>One easy way to do this is to make predictions: &quot;If $THEORY is correct, then under the same conditions, I will observe $OUTCOME.  If $OUTCOME does not obtain, I either haven&#x27;t properly conducted the experiment, or $THEORY is wrong.<p>1.  <a href="https:&#x2F;&#x2F;translate.google.com&#x2F;#auto&#x2F;en&#x2F;assumption" rel="nofollow">https:&#x2F;&#x2F;translate.google.com&#x2F;#auto&#x2F;en&#x2F;assumption</a>
2.  <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Scientific_method" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Scientific_method</a><p>EDIT:<p>In response to your rephrasing of &quot;if...then&quot;, to &quot;assuming...then&quot;, consider that we actually do (or do not) observe $OUTCOME -- we don&#x27;t assume that we observe it.  To use an outrageous (but hopefully clear) example, do we know decapitation is fatal, or do we merely assume it?  A long time ago (but in this galaxy) someone had a theory that decapitation was fatal.  Experimentation gave us knowledge on this issue.  Doubtless, they did not have The Scientific Method in mind, but they used the same process.