If you want to call "free will" the choices that you are determined to pick given your reaction to stimuli, by al means do. They are still determined though.
And this has been demonstrated through various scientific methods across disciplines, such as physics (which is fundamentally indeterministic and at the moment a problematic collection of formalisms which render the very notion of causation an area of contention), neuroscience (in which the basic mechanisms behind information storage, retrieval, and processing are not known, and appear impossible to explain without at the very least quantum-like models), and the life sciences (which is currently going the way of the rest of the physical sciences and adopting models developed within complex systems research).
I mean, it's not as if "Research in biology is often aimed at detangling cause such cause-and-effect chains...However, what we must keep in mind here is that when considering complex phenomena, usually all that can be determined experimentally is whether or not some phenomenon
A and some phenomenon
B exhibit a
correlation...it is quite difficult in studying the kinds of systems considered here to demonstrate cause-effect relations. There are two reasons for this. First, for most processes of interest, there are many causes, and even if for each of these in isolation there may be some clear
if A then B causation, because they, in fact, do not act in isolation but in some collective manner, it is quite difficult to consider only one part of the whole and establish a cuase-effect relation involving it...The second problem that we must consider here is that there are cases in which the variables in question cannot be treated as discrete but continuous, and in such cases,
it is not possible to describe the system in terms of program-like logical relations." pp. 18-19 (italics in original; emphasis added) from
K. Kaneko's Life: An Introduction to Complex Systems Biology (a volume from Springer's edited monograph series
Understanding Complex Systems).
What exactly is the scientific basis, in a world of scientific fields increasingly adopting indeterministic models at the macroscopic level, of applying at best pre-20th century deterministic models to the mind?