Well, if you ask C R or Jabiertxof, Inkscape does have brushes, and will have many more in the future. I did argue the point about this terminology in a long mailing list thread....maybe a year or 2 ago -- alone. Since no one else jumped into the discussion, I assumed that "brushes" was the correct terminology.
My point was that using "brushes" was going to cause Inkscape, a vector graphics editor, to be confused with raster graphics editors. And I dread providing support, and always having to explain the difference. Vector "brushes" and raster brushes are very different things, although they end up creating a similar effect on the canvas.
The calligraphy tool does sort of have brushes, although in the control bar, the menu is...well it doesn't really have a title. But the first choice is "No preset", so I guess they are referred to as "preset" profiles. That's the first item on the left end of the control bar, and the button just to the right of it allows you to either edit or create a new profile. I don't think I've ever used that, but it looks....
Actually it looks like a functionality that has not actually been built into Inkscape yet. I click the button, which produces a small dialog to choose a name for the new profile. But after clicking Save button, nothing else happens. The new name I chose now is showing in the menu, but I don't see how to actually make a new profile. Let's check the manual!
No help there. Maybe you're supposed to create your profile first, and then have it selected while you choose the name for it?? Let's try that....
Hhmm..... That didn't work, although I just edited the vector calligraphy line.
Ooohhh, I think I've got it! You edit all the other options on the control bar, to find the specific kind of profile that you want. THEN you click the button to save the name! It saves the control bar options, so you don't have to remember them.