A force sensing device (1; 101) for a flight control of an aircraft, the force sensing device comprising: - a support, - an action member (7; 107), which is attached to the support while being free to rotate about a primary axis (X13; X113), - a rotary device (9; 109), comprising a stator (51; 151), which is attached to the support while being secured in rotation to the support about a secondary axis (X32; X132), and a rotor (55; 155), which is attached to the stator while being free to rotate relative to the stator about the secondary axis, the rotary device being designed so as to apply a force sensing torque on the rotor, relative to the stator, about the secondary axis, and - a mechanical reducer (11; 111), which relates, with a reduction ratio, the rotation of the action member relative to the support about the primary axis, with the rotation of the rotor relative to the stator about the secondary axis, the mechanical reducer (11; 111) comprising a screw-nut system (21; 121) with rolling elements, which comprises: - a screw (30; 130), which is attached to the rotor (55; 155) while being secured in rotation to the rotor about the secondary axis (X32; X132), and - a nut (40; 140), which is: ∘ fixed in rotation about the secondary axis relative to the stator (51; 151), and ∘ helically linked with the screw about and along the secondary axis, via the rolling elements, the mechanical reducer (11; 111) comprising a connecting rod (19; 119) linking the action member (7; 107) to the nut (40; 140), the connecting rod being attached to the action member, preferably using a first pivot connection (23; 123) which alone connects the connecting rod to the action member, so that the connecting rod is free to rotate relative to the action member about a first connecting rod axis (X23; X123) parallel to the primary axis (X13; X113), the connecting rod (19; 119) being attached to the nut, using a second pivot connection (42; 142) which connects the connecting rod to the nut, so that the connecting rod is free to rotate relative to the nut about a second connecting rod axis (X42; X142) parallel to the primary axis and orthogonal to the secondary axis (X32; X132), the connecting rod forming with the action member a first anti-rotation compass to fasten the nut in rotation about the secondary axis relative to the stator, characterized in that the second pivot connection (42; 142) alone connects the connecting rod (19; 119) to the nut. - a support, - an action member (7; 107), which is attached to the support while being free to rotate about a primary axis (X13; X113), - a rotary device (9; 109), comprising a stator (51; 151), which is attached to the support while being secured in rotation to the support about a secondary axis (X32; X132), and a rotor (55; 155), which is attached to the stator while being free to rotate relative to the stator about the secondary axis, the rotary device being designed so as to apply a force sensing torque on the rotor, relative to the stator, about the secondary axis, and - a mechanical reducer (11; 111), which relates, with a reduction ratio, the rotation of the action member relative to the support about the primary axis, with the rotation of the rotor relative to the stator about the secondary axis, - a screw (30; 130), which is attached to the rotor (55; 155) while being secured in rotation to the rotor about the secondary axis (X32; X132), and - a nut (40; 140), which is: ∘ fixed in rotation about the secondary axis relative to the stator (51; 151), and ∘ helically linked with the screw about and along the secondary axis, via the rolling elements, the mechanical reducer (11; 111) comprising a connecting rod (19; 119) linking the action member (7; 107) to the nut (40; 140), the connecting rod being attached to the action member, preferably using a first pivot connection (23; 123) which alone connects the connecting rod to the action member, so that the connecting rod is free to rotate relative to the action member about a first connecting rod axis (X23; X123) parallel to the primary axis (X13; X113), the connecting rod (19; 119) being attached to the nut, using a second pivot connection (42; 142) which connects the connecting rod to the nut, so that the connecting rod is free to rotate relative to the nut about a second connecting rod axis (X42; X142) parallel to the primary axis and orthogonal to the secondary axis (X32; X132), the connecting rod forming with the action member a first anti-rotation compass to fasten the nut in rotation about the secondary axis relative to the stator, characterized in that the second pivot connection (42; 142) alone connects the connecting rod (19; 119) to the nut. ∘ fixed in rotation about the secondary axis relative to the stator (51; 151), and ∘ helically linked with the screw about and along the secondary axis, via the rolling elements,