English as foreign language (EFL) writers are often found to have weaker control of their academic writing, among which presenting an effective authorial stance has been reported as particularly challenging (Hyland, 1998a; Schleppegrell, 2004). In particular, student writers tended to deploy a stronger stance and be less effective with tentative claims. The study investigated a small group of EFL doctoral students' conceptions, which, as hypothesized, may affect their presentation of stance in academic arguments. Twelve doctoral candidates were recruited from two disciplines, soft and hard sciences. They answered questions and made judgments related to authorial stance, adapted into two "extreme" versions, assertive and tentative, in academic texts taken from both domain-specific and domain-neutral journal articles. The results revealed that the doctoral participants' conceptions pertained to three dimensions, "Stance as linguistic construct," "as cognitive or behavioural entity" and "as institutional norm." Their conceptions generally lacked sophistication and depth and instead were reductive and polarized. Assertive claims obtained more favourable considerations than tentative claims, and students from both disciplines varied considerably in their views of language. The results can inform academic stance instruction to allow for more exposure to nuanced presentations of stance and engagement with explicit discussions of the nuances of stance-taking.