The answer to the question, “Is Roger Bacon’s scientific practice scientific?” concerns an assessment of whether Bacon’s scientific practice exhibits traits of modern science. This paper uses the theoretical framework proposed by Hon and Goldstein (2023) for defining modern science, which identifies three salient, constitutive features: commitment, methodology and technique. These features function together as a skeleton of the argumentative structure which combines presuppositions and rules of inference to reach a conclusion. The fundamental assumption is that scientific knowledge is argumentative. Against this background we examine three scientific results that Bacon included in his Opus majus. Although Bacon’s methodology involves the use of geometrical proofs and his technique employs diagrams and geometrical analysis of the relations embedded in them—both features seemingly indicative of modern scientific practice—a characteristic alien to modern practice surfaces in the feature Hon and Goldstein refer to as “commitment.” Specifically, Bacon’s commitment is rooted in theology and its dependence on sacred scripture. It is this characteristic that sets Bacon’s scientific practice apart from modern science. In a nutshell, Bacon’s commitment implies that final causes are not directly and fully known from the natural world but are revealed through scripture. Consequently, since understanding the nature of a thing requires knowing all four Aristotelian causes, those ignorant of sacred scripture cannot grasp the final cause and thus miss the true nature of the thing. It thus follows that Bacon’s approach is not what we associate with modern science.

We investigate the existence of a rainbow Hamilton cycle in a uniformly edge-coloured randomly perturbed digraph. We show that for every $\delta \in (0,1)$ there exists $C = C(\delta ) \gt 0$ such that the following holds. Let $D_0$ be an $n$-vertex digraph with minimum semidegree at least $\delta n$ and suppose that each edge of the union of $D_0$ with a copy of the random digraph $\mathbf{D}(n,C/n)$ on the same vertex set gets a colour in $[n]$ independently and uniformly at random. Then, with high probability, $D_0 \cup \mathbf{D}(n,C/n)$ has a rainbow directed Hamilton cycle.

This improves a result of Aigner-Horev and Hefetz ((2021) SIAM J. Discrete Math. 35(3) 1569–1577), who proved the same in the undirected setting when the edges are coloured uniformly in a set of $(1 + \varepsilon )n$ colours.