When one talks about a SE discipline it's good to know whether we're in academic or industrial settings.
Academic engineering is a pretty new thing - once the engineers were educated by apprenticeships not by universities.
I think that in industry the SE is assigned rather specific task in the new product development process - in the defence setting the SE tasks are even mandated.
In academy the situation is different. What is Electronics Engineering Research if not the search of the new electronic technologies - sometimes the advances in physics are needed to advance the electronics but not always - so that's application of science not discovery.
The "hard engineering" disciplines are rooted in the exact sciences. That's not so for SE - the scientific component of the SE borders (some say lays in) social sciences domain - sore spot for academicians that thrive to belong to the Engineering part of the campus near the Physics, Chemistry etc buildings. The same challenge is faced by the Industrial Engineering practitioners and researchers.
So until we don't admit that SE science is inherently social we'll be stuck. Let's be true to ourselves - SE science is the science of social behavior of large groups of technical practitioners and managers (project teams) engaged in solving complex problems for other groups of people (stakeholders) by defining, developing, integrating and putting to use physical artefacts (systems).