Is the default in human actions permissibility or prohibition?

The principle "The default ruling for things is permissibility" is one of the major jurisprudential maxims. A corollary of this is that the default ruling for transactions is permissibility unless there is evidence of their prohibition. Exceptions to this include principles such as: "The default ruling for intimate relations is prohibition," "The default ruling for acts of worship is prohibition [unless prescribed]," "The default ruling for slaughtered animals is prohibition [unless ritually slaughtered]," and "It is not permissible to dispose of another's property except with their permission." Accordingly, new contracts are permissible unless they involve religiously prohibited elements such as excessive ambiguity (Jahalah), gharar (excessive uncertainty/risk), riba (interest), tadlis (deception), and gish (fraud).