Fisher v Bell  QB 394
FORMATION OF CONTRACT
The defendant shopkeeper displayed in his shop window a flick knife accompanied by a price ticket displayed just behind it. He was charged with offering for sale a flick knife, contrary to s. 1 (1) of the Restriction of Offensive Weapons Act 1959.
The issue was whether the display of the knife constituted an offer for sale (in which case the defendant was guilty) or an invitation to treat (in which case he was not).
The court held that in accordance with the general principles of contract law, the display of the knife was not an offer of sale but merely an invitation to treat, and as such the defendant had not offered the knife for sale within the meaning of s1(1) of the Act. Although it was acknowledged that in ordinary language a layman might consider the knife to be offered for sale, in legal terms its position in the window was inviting customers to offer to buy it. The statute must be construed in accordance with the legal meaning, as
“…any statute must be looked at in light of the general law of the country, for Parliament must be taken to know the general law” (per Lord Parker C.J. at para. 4).
It is well established in contract law that the display of an item in a shop window is an invitation to potential customers to treat. The defendant was therefore not guilty of the offence with which he had been charged.